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<div class="titlepage"><div><div><h3 class="title">
<a name="boost_regex.ref.regex_search"></a><a class="link" href="regex_search.html" title="regex_search">regex_search</a>
</h3></div></div></div>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">regex</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
</pre>
<p>
        The algorithm <a class="link" href="regex_search.html" title="regex_search"><code class="computeroutput"><span class="identifier">regex_search</span></code></a> will search a range
        denoted by a pair of bidirectional-iterators for a given regular expression.
        The algorithm uses various heuristics to reduce the search time by only checking
        for a match if a match could conceivably start at that position. The algorithm
        is defined as follows:
      </p>
<pre class="programlisting"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">BidirectionalIterator</span><span class="special">,</span>
         <span class="keyword">class</span> <span class="identifier">Allocator</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">charT</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">traits</span><span class="special">&gt;</span>
<span class="keyword">bool</span> <span class="identifier">regex_search</span><span class="special">(</span><span class="identifier">BidirectionalIterator</span> <span class="identifier">first</span><span class="special">,</span> <span class="identifier">BidirectionalIterator</span> <span class="identifier">last</span><span class="special">,</span>
                  <span class="identifier">match_results</span><span class="special">&lt;</span><span class="identifier">BidirectionalIterator</span><span class="special">,</span> <span class="identifier">Allocator</span><span class="special">&gt;&amp;</span> <span class="identifier">m</span><span class="special">,</span>
                  <span class="keyword">const</span> <span class="identifier">basic_regex</span><span class="special">&lt;</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">traits</span><span class="special">&gt;&amp;</span> <span class="identifier">e</span><span class="special">,</span>
                  <span class="identifier">match_flag_type</span> <span class="identifier">flags</span> <span class="special">=</span> <span class="identifier">match_default</span><span class="special">);</span>

<span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">ST</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">SA</span><span class="special">,</span>
         <span class="keyword">class</span> <span class="identifier">Allocator</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">charT</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">traits</span><span class="special">&gt;</span>
<span class="keyword">bool</span> <span class="identifier">regex_search</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">basic_string</span><span class="special">&lt;</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">ST</span><span class="special">,</span> <span class="identifier">SA</span><span class="special">&gt;&amp;</span> <span class="identifier">s</span><span class="special">,</span>
                  <span class="identifier">match_results</span><span class="special">&lt;</span>
                  <span class="keyword">typename</span> <span class="identifier">basic_string</span><span class="special">&lt;</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">ST</span><span class="special">,</span><span class="identifier">SA</span><span class="special">&gt;::</span><span class="identifier">const_iterator</span><span class="special">,</span>
                  <span class="identifier">Allocator</span><span class="special">&gt;&amp;</span> <span class="identifier">m</span><span class="special">,</span>
                  <span class="keyword">const</span> <span class="identifier">basic_regex</span><span class="special">&lt;</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">traits</span><span class="special">&gt;&amp;</span> <span class="identifier">e</span><span class="special">,</span>
                  <span class="identifier">match_flag_type</span> <span class="identifier">flags</span> <span class="special">=</span> <span class="identifier">match_default</span><span class="special">);</span>

<span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">charT</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">Allocator</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">traits</span><span class="special">&gt;</span>
<span class="keyword">bool</span> <span class="identifier">regex_search</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">charT</span><span class="special">*</span> <span class="identifier">str</span><span class="special">,</span>
                  <span class="identifier">match_results</span><span class="special">&lt;</span><span class="keyword">const</span> <span class="identifier">charT</span><span class="special">*,</span> <span class="identifier">Allocator</span><span class="special">&gt;&amp;</span> <span class="identifier">m</span><span class="special">,</span>
                  <span class="keyword">const</span> <span class="identifier">basic_regex</span><span class="special">&lt;</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">traits</span><span class="special">&gt;&amp;</span> <span class="identifier">e</span><span class="special">,</span>
                  <span class="identifier">match_flag_type</span> <span class="identifier">flags</span> <span class="special">=</span> <span class="identifier">match_default</span><span class="special">);</span>

<span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">BidirectionalIterator</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">charT</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">traits</span><span class="special">&gt;</span>
<span class="keyword">bool</span> <span class="identifier">regex_search</span><span class="special">(</span><span class="identifier">BidirectionalIterator</span> <span class="identifier">first</span><span class="special">,</span> <span class="identifier">BidirectionalIterator</span> <span class="identifier">last</span><span class="special">,</span>
                  <span class="keyword">const</span> <span class="identifier">basic_regex</span><span class="special">&lt;</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">traits</span><span class="special">&gt;&amp;</span> <span class="identifier">e</span><span class="special">,</span>
                  <span class="identifier">match_flag_type</span> <span class="identifier">flags</span> <span class="special">=</span> <span class="identifier">match_default</span><span class="special">);</span>

<span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">charT</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">traits</span><span class="special">&gt;</span>
<span class="keyword">bool</span> <span class="identifier">regex_search</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">charT</span><span class="special">*</span> <span class="identifier">str</span><span class="special">,</span>
                  <span class="keyword">const</span> <span class="identifier">basic_regex</span><span class="special">&lt;</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">traits</span><span class="special">&gt;&amp;</span> <span class="identifier">e</span><span class="special">,</span>
                  <span class="identifier">match_flag_type</span> <span class="identifier">flags</span> <span class="special">=</span> <span class="identifier">match_default</span><span class="special">);</span>

<span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">ST</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">SA</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">charT</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">traits</span><span class="special">&gt;</span>
<span class="keyword">bool</span> <span class="identifier">regex_search</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">basic_string</span><span class="special">&lt;</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">ST</span><span class="special">,</span> <span class="identifier">SA</span><span class="special">&gt;&amp;</span> <span class="identifier">s</span><span class="special">,</span>
                  <span class="keyword">const</span> <span class="identifier">basic_regex</span><span class="special">&lt;</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">traits</span><span class="special">&gt;&amp;</span> <span class="identifier">e</span><span class="special">,</span>
                  <span class="identifier">match_flag_type</span> <span class="identifier">flags</span> <span class="special">=</span> <span class="identifier">match_default</span><span class="special">);</span>
</pre>
<h5>
<a name="boost_regex.ref.regex_search.h0"></a>
        <span class="phrase"><a name="boost_regex.ref.regex_search.description"></a></span><a class="link" href="regex_search.html#boost_regex.ref.regex_search.description">Description</a>
      </h5>
<pre class="programlisting"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">BidirectionalIterator</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">Allocator</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">charT</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">traits</span><span class="special">&gt;</span>
<span class="keyword">bool</span> <span class="identifier">regex_search</span><span class="special">(</span><span class="identifier">BidirectionalIterator</span> <span class="identifier">first</span><span class="special">,</span> <span class="identifier">BidirectionalIterator</span> <span class="identifier">last</span><span class="special">,</span>
                  <span class="identifier">match_results</span><span class="special">&lt;</span><span class="identifier">BidirectionalIterator</span><span class="special">,</span> <span class="identifier">Allocator</span><span class="special">&gt;&amp;</span> <span class="identifier">m</span><span class="special">,</span>
                  <span class="keyword">const</span> <span class="identifier">basic_regex</span><span class="special">&lt;</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">traits</span><span class="special">&gt;&amp;</span> <span class="identifier">e</span><span class="special">,</span>
                  <span class="identifier">match_flag_type</span> <span class="identifier">flags</span> <span class="special">=</span> <span class="identifier">match_default</span><span class="special">);</span>
</pre>
<p>
        <span class="bold"><strong>Requires</strong></span>: Type BidirectionalIterator meets
        the requirements of a Bidirectional Iterator (24.1.4).
      </p>
<p>
        <span class="bold"><strong>Effects</strong></span>: Determines whether there is some
        sub-sequence within [first,last) that matches the regular expression <span class="emphasis"><em>e</em></span>,
        parameter <span class="emphasis"><em>flags</em></span> is used to control how the expression
        is matched against the character sequence. Returns true if such a sequence
        exists, false otherwise.
      </p>
<p>
        <span class="bold"><strong>Throws</strong></span>: <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">runtime_error</span></code>
        if the complexity of matching the expression against an N character string
        begins to exceed O(N<sup>2</sup>), or if the program runs out of stack space while matching
        the expression (if Boost.Regex is configured in recursive mode), or if the
        matcher exhausts its permitted memory allocation (if Boost.Regex is configured
        in non-recursive mode).
      </p>
<p>
        <span class="bold"><strong>Postconditions</strong></span>: If the function returns
        false, then the effect on parameter <span class="emphasis"><em>m</em></span> is undefined,
        otherwise the effects on parameter <span class="emphasis"><em>m</em></span> are given in the
        table:
      </p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead><tr>
<th>
                <p>
                  Element
                </p>
              </th>
<th>
                <p>
                  Value
                </p>
              </th>
</tr></thead>
<tbody>
<tr>
<td>
                <p>
                  <code class="computeroutput"><span class="identifier">m</span><span class="special">.</span><span class="identifier">size</span><span class="special">()</span></code>
                </p>
              </td>
<td>
                <p>
                  <code class="computeroutput"><span class="number">1</span> <span class="special">+</span>
                  <span class="identifier">e</span><span class="special">.</span><span class="identifier">mark_count</span><span class="special">()</span></code>
                </p>
              </td>
</tr>
<tr>
<td>
                <p>
                  <code class="computeroutput"><span class="identifier">m</span><span class="special">.</span><span class="identifier">empty</span><span class="special">()</span></code>
                </p>
              </td>
<td>
                <p>
                  <code class="computeroutput"><span class="keyword">false</span></code>
                </p>
              </td>
</tr>
<tr>
<td>
                <p>
                  <code class="computeroutput"><span class="identifier">m</span><span class="special">.</span><span class="identifier">prefix</span><span class="special">().</span><span class="identifier">first</span></code>
                </p>
              </td>
<td>
                <p>
                  <code class="computeroutput"><span class="identifier">first</span></code>
                </p>
              </td>
</tr>
<tr>
<td>
                <p>
                  <code class="computeroutput"><span class="identifier">m</span><span class="special">.</span><span class="identifier">prefix</span><span class="special">().</span><span class="identifier">second</span></code>
                </p>
              </td>
<td>
                <p>
                  <code class="computeroutput"><span class="identifier">m</span><span class="special">[</span><span class="number">0</span><span class="special">].</span><span class="identifier">first</span></code>
                </p>
              </td>
</tr>
<tr>
<td>
                <p>
                  <code class="computeroutput"><span class="identifier">m</span><span class="special">.</span><span class="identifier">prefix</span><span class="special">().</span><span class="identifier">matched</span></code>
                </p>
              </td>
<td>
                <p>
                  <code class="computeroutput"><span class="identifier">m</span><span class="special">.</span><span class="identifier">prefix</span><span class="special">().</span><span class="identifier">first</span> <span class="special">!=</span>
                  <span class="identifier">m</span><span class="special">.</span><span class="identifier">prefix</span><span class="special">().</span><span class="identifier">second</span></code>
                </p>
              </td>
</tr>
<tr>
<td>
                <p>
                  <code class="computeroutput"><span class="identifier">m</span><span class="special">.</span><span class="identifier">suffix</span><span class="special">().</span><span class="identifier">first</span></code>
                </p>
              </td>
<td>
                <p>
                  <code class="computeroutput"><span class="identifier">m</span><span class="special">[</span><span class="number">0</span><span class="special">].</span><span class="identifier">second</span></code>
                </p>
              </td>
</tr>
<tr>
<td>
                <p>
                  <code class="computeroutput"><span class="identifier">m</span><span class="special">.</span><span class="identifier">suffix</span><span class="special">().</span><span class="identifier">second</span></code>
                </p>
              </td>
<td>
                <p>
                  <code class="computeroutput"><span class="identifier">last</span></code>
                </p>
              </td>
</tr>
<tr>
<td>
                <p>
                  <code class="computeroutput"><span class="identifier">m</span><span class="special">.</span><span class="identifier">suffix</span><span class="special">().</span><span class="identifier">matched</span></code>
                </p>
              </td>
<td>
                <p>
                  <code class="computeroutput"><span class="identifier">m</span><span class="special">.</span><span class="identifier">suffix</span><span class="special">().</span><span class="identifier">first</span> <span class="special">!=</span>
                  <span class="identifier">m</span><span class="special">.</span><span class="identifier">suffix</span><span class="special">().</span><span class="identifier">second</span></code>
                </p>
              </td>
</tr>
<tr>
<td>
                <p>
                  <code class="computeroutput"><span class="identifier">m</span><span class="special">[</span><span class="number">0</span><span class="special">].</span><span class="identifier">first</span></code>
                </p>
              </td>
<td>
                <p>
                  The start of the sequence of characters that matched the regular
                  expression
                </p>
              </td>
</tr>
<tr>
<td>
                <p>
                  <code class="computeroutput"><span class="identifier">m</span><span class="special">[</span><span class="number">0</span><span class="special">].</span><span class="identifier">second</span></code>
                </p>
              </td>
<td>
                <p>
                  The end of the sequence of characters that matched the regular
                  expression
                </p>
              </td>
</tr>
<tr>
<td>
                <p>
                  <code class="computeroutput"><span class="identifier">m</span><span class="special">[</span><span class="number">0</span><span class="special">].</span><span class="identifier">matched</span></code>
                </p>
              </td>
<td>
                <p>
                  true if a full match was found, and false if it was a partial match
                  (found as a result of the match_partial flag being set).
                </p>
              </td>
</tr>
<tr>
<td>
                <p>
                  <code class="computeroutput"><span class="identifier">m</span><span class="special">[</span><span class="identifier">n</span><span class="special">].</span><span class="identifier">first</span></code>
                </p>
              </td>
<td>
                <p>
                  For all integers <code class="computeroutput"><span class="identifier">n</span> <span class="special">&lt;</span> <span class="identifier">m</span><span class="special">.</span><span class="identifier">size</span><span class="special">()</span></code>, the start of the sequence that
                  matched sub-expression <span class="emphasis"><em>n</em></span>. Alternatively, if
                  sub-expression <span class="emphasis"><em>n</em></span> did not participate in the
                  match, then last.
                </p>
              </td>
</tr>
<tr>
<td>
                <p>
                  <code class="computeroutput"><span class="identifier">m</span><span class="special">[</span><span class="identifier">n</span><span class="special">].</span><span class="identifier">second</span></code>
                </p>
              </td>
<td>
                <p>
                  For all integers <code class="computeroutput"><span class="identifier">n</span> <span class="special">&lt;</span> <span class="identifier">m</span><span class="special">.</span><span class="identifier">size</span><span class="special">()</span></code>, the end of the sequence that
                  matched sub-expression <span class="emphasis"><em>n</em></span>. Alternatively, if
                  sub-expression <span class="emphasis"><em>n</em></span> did not participate in the
                  match, then <code class="computeroutput"><span class="identifier">last</span></code>.
                </p>
              </td>
</tr>
<tr>
<td>
                <p>
                  <code class="computeroutput"><span class="identifier">m</span><span class="special">[</span><span class="identifier">n</span><span class="special">].</span><span class="identifier">matched</span></code>
                </p>
              </td>
<td>
                <p>
                  For all integers <code class="computeroutput"><span class="identifier">n</span> <span class="special">&lt;</span> <span class="identifier">m</span><span class="special">.</span><span class="identifier">size</span><span class="special">()</span></code>, true if sub-expression <span class="emphasis"><em>n</em></span>
                  participated in the match, false otherwise.
                </p>
              </td>
</tr>
</tbody>
</table></div>
<pre class="programlisting"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">charT</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">Allocator</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">traits</span><span class="special">&gt;</span>
<span class="keyword">bool</span> <span class="identifier">regex_search</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">charT</span><span class="special">*</span> <span class="identifier">str</span><span class="special">,</span> <span class="identifier">match_results</span><span class="special">&lt;</span><span class="keyword">const</span> <span class="identifier">charT</span><span class="special">*,</span> <span class="identifier">Allocator</span><span class="special">&gt;&amp;</span> <span class="identifier">m</span><span class="special">,</span>
                  <span class="keyword">const</span> <span class="identifier">basic_regex</span><span class="special">&lt;</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">traits</span><span class="special">&gt;&amp;</span> <span class="identifier">e</span><span class="special">,</span>
                  <span class="identifier">match_flag_type</span> <span class="identifier">flags</span> <span class="special">=</span> <span class="identifier">match_default</span><span class="special">);</span>
</pre>
<p>
        <span class="bold"><strong>Effects</strong></span>: Returns the result of <code class="computeroutput"><span class="identifier">regex_search</span><span class="special">(</span><span class="identifier">str</span><span class="special">,</span> <span class="identifier">str</span>
        <span class="special">+</span> <span class="identifier">char_traits</span><span class="special">&lt;</span><span class="identifier">charT</span><span class="special">&gt;::</span><span class="identifier">length</span><span class="special">(</span><span class="identifier">str</span><span class="special">),</span>
        <span class="identifier">m</span><span class="special">,</span> <span class="identifier">e</span><span class="special">,</span> <span class="identifier">flags</span><span class="special">)</span></code>.
      </p>
<pre class="programlisting"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">ST</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">SA</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">Allocator</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">charT</span><span class="special">,</span>
         <span class="keyword">class</span> <span class="identifier">traits</span><span class="special">&gt;</span>
<span class="keyword">bool</span> <span class="identifier">regex_search</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">basic_string</span><span class="special">&lt;</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">ST</span><span class="special">,</span> <span class="identifier">SA</span><span class="special">&gt;&amp;</span> <span class="identifier">s</span><span class="special">,</span>
                  <span class="identifier">match_results</span><span class="special">&lt;</span><span class="keyword">typename</span> <span class="identifier">basic_string</span><span class="special">&lt;</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">ST</span><span class="special">,</span> <span class="identifier">SA</span><span class="special">&gt;::</span><span class="identifier">const_iterator</span><span class="special">,</span> <span class="identifier">Allocator</span><span class="special">&gt;&amp;</span> <span class="identifier">m</span><span class="special">,</span>
                  <span class="keyword">const</span> <span class="identifier">basic_regex</span><span class="special">&lt;</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">traits</span><span class="special">&gt;&amp;</span> <span class="identifier">e</span><span class="special">,</span>
                  <span class="identifier">match_flag_type</span> <span class="identifier">flags</span> <span class="special">=</span> <span class="identifier">match_default</span><span class="special">);</span>
</pre>
<p>
        <span class="bold"><strong>Effects</strong></span>: Returns the result of <code class="computeroutput"><span class="identifier">regex_search</span><span class="special">(</span><span class="identifier">s</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(),</span> <span class="identifier">s</span><span class="special">.</span><span class="identifier">end</span><span class="special">(),</span> <span class="identifier">m</span><span class="special">,</span> <span class="identifier">e</span><span class="special">,</span> <span class="identifier">flags</span><span class="special">)</span></code>.
      </p>
<pre class="programlisting"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">iterator</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">charT</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">traits</span><span class="special">&gt;</span>
<span class="keyword">bool</span> <span class="identifier">regex_search</span><span class="special">(</span><span class="identifier">iterator</span> <span class="identifier">first</span><span class="special">,</span> <span class="identifier">iterator</span> <span class="identifier">last</span><span class="special">,</span>
                  <span class="keyword">const</span> <span class="identifier">basic_regex</span><span class="special">&lt;</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">traits</span><span class="special">&gt;&amp;</span> <span class="identifier">e</span><span class="special">,</span>
                  <span class="identifier">match_flag_type</span> <span class="identifier">flags</span> <span class="special">=</span> <span class="identifier">match_default</span><span class="special">);</span>
</pre>
<p>
        <span class="bold"><strong>Effects</strong></span>: Behaves "as if" by constructing
        an instance of <code class="computeroutput"><span class="identifier">match_results</span><span class="special">&lt;</span><span class="identifier">BidirectionalIterator</span><span class="special">&gt;</span> <span class="identifier">what</span></code>,
        and then returning the result of <code class="computeroutput"><span class="identifier">regex_search</span><span class="special">(</span><span class="identifier">first</span><span class="special">,</span> <span class="identifier">last</span><span class="special">,</span> <span class="identifier">what</span><span class="special">,</span> <span class="identifier">e</span><span class="special">,</span>
        <span class="identifier">flags</span><span class="special">)</span></code>.
      </p>
<pre class="programlisting"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">charT</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">traits</span><span class="special">&gt;</span>
<span class="keyword">bool</span> <span class="identifier">regex_search</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">charT</span><span class="special">*</span> <span class="identifier">str</span>
                  <span class="keyword">const</span> <span class="identifier">basic_regex</span><span class="special">&lt;</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">traits</span><span class="special">&gt;&amp;</span> <span class="identifier">e</span><span class="special">,</span>
                  <span class="identifier">match_flag_type</span> <span class="identifier">flags</span> <span class="special">=</span> <span class="identifier">match_default</span><span class="special">);</span>
</pre>
<p>
        <span class="bold"><strong>Effects</strong></span>: Returns the result of <code class="computeroutput"><span class="identifier">regex_search</span><span class="special">(</span><span class="identifier">str</span><span class="special">,</span> <span class="identifier">str</span>
        <span class="special">+</span> <span class="identifier">char_traits</span><span class="special">&lt;</span><span class="identifier">charT</span><span class="special">&gt;::</span><span class="identifier">length</span><span class="special">(</span><span class="identifier">str</span><span class="special">),</span>
        <span class="identifier">e</span><span class="special">,</span> <span class="identifier">flags</span><span class="special">)</span></code>.
      </p>
<pre class="programlisting"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">ST</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">SA</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">charT</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">traits</span><span class="special">&gt;</span>
<span class="keyword">bool</span> <span class="identifier">regex_search</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">basic_string</span><span class="special">&lt;</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">ST</span><span class="special">,</span> <span class="identifier">SA</span><span class="special">&gt;&amp;</span> <span class="identifier">s</span><span class="special">,</span>
                  <span class="keyword">const</span> <span class="identifier">basic_regex</span><span class="special">&lt;</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">traits</span><span class="special">&gt;&amp;</span> <span class="identifier">e</span><span class="special">,</span>
                  <span class="identifier">match_flag_type</span> <span class="identifier">flags</span> <span class="special">=</span> <span class="identifier">match_default</span><span class="special">);</span>
</pre>
<p>
        <span class="bold"><strong>Effects</strong></span>: Returns the result of <code class="computeroutput"><span class="identifier">regex_search</span><span class="special">(</span><span class="identifier">s</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(),</span> <span class="identifier">s</span><span class="special">.</span><span class="identifier">end</span><span class="special">(),</span> <span class="identifier">e</span><span class="special">,</span> <span class="identifier">flags</span><span class="special">)</span></code>.
      </p>
<h5>
<a name="boost_regex.ref.regex_search.h1"></a>
        <span class="phrase"><a name="boost_regex.ref.regex_search.examples"></a></span><a class="link" href="regex_search.html#boost_regex.ref.regex_search.examples">Examples</a>
      </h5>
<p>
        The following example, takes the contents of a file in the form of a string,
        and searches for all the C++ class declarations in the file. The code will
        work regardless of the way that <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span></code>
        is implemented, for example it could easily be modified to work with the
        SGI rope class, which uses a non-contiguous storage strategy.
      </p>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">string</span><span class="special">&gt;</span>
<span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">map</span><span class="special">&gt;</span>
<span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">regex</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>

<span class="comment">// purpose: </span>
<span class="comment">// takes the contents of a file in the form of a string </span>
<span class="comment">// and searches for all the C++ class definitions, storing </span>
<span class="comment">// their locations in a map of strings/int's </span>
<span class="keyword">typedef</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">map</span><span class="special">&lt;</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">,</span> <span class="keyword">int</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">less</span><span class="special">&lt;</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">&gt;</span> <span class="special">&gt;</span> <span class="identifier">map_type</span><span class="special">;</span>

<span class="identifier">boost</span><span class="special">::</span><span class="identifier">regex</span> <span class="identifier">expression</span><span class="special">(</span>
   <span class="string">"^(template[[:space:]]*&lt;[^;:{]+&gt;[[:space:]]*)?"</span>
   <span class="string">"(class|struct)[[:space:]]*"</span>
   <span class="string">"(\\&lt;\\w+\\&gt;([[:blank:]]*\\([^)]*\\))?"</span>
   <span class="string">"[[:space:]]*)*(\\&lt;\\w*\\&gt;)[[:space:]]*"</span>
   <span class="string">"(&lt;[^;:{]+&gt;[[:space:]]*)?(\\{|:[^;\\{()]*\\{)"</span><span class="special">);</span>

<span class="keyword">void</span> <span class="identifier">IndexClasses</span><span class="special">(</span><span class="identifier">map_type</span><span class="special">&amp;</span> <span class="identifier">m</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">&amp;</span> <span class="identifier">file</span><span class="special">)</span>
<span class="special">{</span>
   <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">::</span><span class="identifier">const_iterator</span> <span class="identifier">start</span><span class="special">,</span> <span class="identifier">end</span><span class="special">;</span>
   <span class="identifier">start</span> <span class="special">=</span> <span class="identifier">file</span><span class="special">.</span><span class="identifier">begin</span><span class="special">();</span>
   <span class="identifier">end</span> <span class="special">=</span> <span class="identifier">file</span><span class="special">.</span><span class="identifier">end</span><span class="special">();</span>
      <span class="identifier">boost</span><span class="special">::</span><span class="identifier">match_results</span><span class="special">&lt;</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">::</span><span class="identifier">const_iterator</span><span class="special">&gt;</span> <span class="identifier">what</span><span class="special">;</span>
   <span class="identifier">boost</span><span class="special">::</span><span class="identifier">match_flag_type</span> <span class="identifier">flags</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">match_default</span><span class="special">;</span>
   <span class="keyword">while</span><span class="special">(</span><span class="identifier">regex_search</span><span class="special">(</span><span class="identifier">start</span><span class="special">,</span> <span class="identifier">end</span><span class="special">,</span> <span class="identifier">what</span><span class="special">,</span> <span class="identifier">expression</span><span class="special">,</span> <span class="identifier">flags</span><span class="special">))</span>
   <span class="special">{</span>
      <span class="comment">// what[0] contains the whole string </span>
      <span class="comment">// what[5] contains the class name. </span>
      <span class="comment">// what[6] contains the template specialisation if any. </span>
      <span class="comment">// add class name and position to map: </span>
      <span class="identifier">m</span><span class="special">[</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">(</span><span class="identifier">what</span><span class="special">[</span><span class="number">5</span><span class="special">].</span><span class="identifier">first</span><span class="special">,</span> <span class="identifier">what</span><span class="special">[</span><span class="number">5</span><span class="special">].</span><span class="identifier">second</span><span class="special">)</span>
            <span class="special">+</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">(</span><span class="identifier">what</span><span class="special">[</span><span class="number">6</span><span class="special">].</span><span class="identifier">first</span><span class="special">,</span> <span class="identifier">what</span><span class="special">[</span><span class="number">6</span><span class="special">].</span><span class="identifier">second</span><span class="special">)]</span>
         <span class="special">=</span> <span class="identifier">what</span><span class="special">[</span><span class="number">5</span><span class="special">].</span><span class="identifier">first</span> <span class="special">-</span> <span class="identifier">file</span><span class="special">.</span><span class="identifier">begin</span><span class="special">();</span>
      <span class="comment">// update search position: </span>
      <span class="identifier">start</span> <span class="special">=</span> <span class="identifier">what</span><span class="special">[</span><span class="number">0</span><span class="special">].</span><span class="identifier">second</span><span class="special">;</span>
      <span class="comment">// update flags: </span>
      <span class="identifier">flags</span> <span class="special">|=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">match_prev_avail</span><span class="special">;</span>
      <span class="identifier">flags</span> <span class="special">|=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">match_not_bob</span><span class="special">;</span>
   <span class="special">}</span>
<span class="special">}</span>
</pre>
</div>
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<td align="right"><div class="copyright-footer">Copyright © 1998-2013 John Maddock<p>
        Distributed under the Boost Software License, Version 1.0. (See accompanying
        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
      </p>
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